Heterogeneity of glucose-6-phosphate dehydrogenase enzymopathies in the CSSR

GdB- variants of 7 patients from the CSSR have been isolated and characterized kinetically. The properties of these G6PD variants differ phenotypically. Among them we found both a variant with a very high Km G6P and a severe chronic hemolytic anemia and one patient with a low Km G6P variant and only intermittent hemolytic crises and moderate hyperbilirubinemia. The low-Km enzyme corresponds to GdMediterranean like variants with a high utilization of substrate analoga and a biphasic pH profile. A third GdB- variant exhibits a low NADP affinity and high inhibition by ATP. A noticeable low utilization of the analogon dNADP was detectable for two enzymes of heterozygotes.